• Title/Summary/Keyword: Normal variability

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Nonlinear Conte-Zbilut-Federici (CZF) Method of Computing LF/HF Ratio: A More Reliable Index of Changes in Heart Rate Variability

  • Vernon Bond, Jr;Curry, Bryan H;Kumar, Krishna;Pemminati, Sudhakar;Gorantla, Vasavi R;Kadur, Kishan;Millis, Richard M
    • Journal of Pharmacopuncture
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    • v.19 no.3
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    • pp.207-212
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    • 2016
  • Objectives: Acupuncture treatments are safe and effective for a wide variety of diseases involving autonomic dysregulation. Heart rate variability (HRV) is a noninvasive method for assessing sympathovagal balance. The low frequency/high frequency (LF/HF) spectral power ratio is an index of sympathovagal influence on heart rate and of cardiovascular health. This study tests the hypothesis that from rest to 30% to 50% of peak oxygen consumption, the nonlinear Conte-Zbilut-Federici (CZF) method of computing the LF/HF ratio is a more reliable index of changes in the HRV than linear methods are. Methods: The subjects of this study were 10 healthy young adults. Electrocardiogram RR intervals were measured during 6-minute periods of rest and aerobic exercise on a cycle ergometer at 30% and 50% of peak oxygen consumption ($VO_{2peak}$). Results: The frequency domain CZF computations of the LF/HF ratio and the time domain computations of the standard deviation of normal-to-normal intervals (SDNN) decreased sequentially from rest to 30% $VO_{2peak}$ (P < 0.001) to 50% $VO_{2peak}$ (P < 0.05). The SDNN and the CZF computations of the LF/HF ratio were positively correlated (Pearson's r = 0.75, P < 0.001). fast Fourier transform (FFT), autoregressive (AR) and Lomb periodogram computations of the LF/HF ratio increased only from rest to 50% $VO_{2peak}$. Conclusion: Computations of the LF/HF ratio by using the nonlinear CZF method appear to be more sensitive to changes in physical activity than computations of the LF/HF ratio by using linear methods. Future studies should determine whether the CZF computation of the LF/HF ratio improves evaluations of pharmacopuncture and other treatment modalities.

A Study on the Relation between Anemia and Heart Rate Variability in Postpartum Women (산모에서 빈혈과 심박변이도의 관계 연구)

  • Song, Yun-Hui;Kim, Tae-Hee
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.1
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    • pp.199-213
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    • 2007
  • Purpose : This research was designed to determine whether HRV can be used as an assessment index in weakly postpartum women. Methods : The subjects were 232 women who admitted for postpartum care in Oriental Hospital of Woosuk University from 19, December 2005 to 21, July 2006. They took the test of CBC and HRV. And then we selected 200 cases of postpartum women. The SPSS 10.0 for windows was used to analyse the data and the simple correlation coefficient and the independent samples t-test were used to verify the results. Results : The following results were obtained : 1. There were positive correlations between items of CBC(RBC, Hb, Hct) and SDSD, RMSSD, SDNN, and also between items of CBC and log-transformed index of spectral analysis. There were negative correlations between items of CBC and Mean-HRV, pNN50. 2. SDNN of anemic postpartum women group significantly decreased compared with that of normal postpartum women group. HRV-Index, RMSSD and SDSD of anemic postpartum women group significantly decreased compared with that of normal postpartum women group. pNN50 of anemic postpartum women group significantly increased compared with that of normal postpartum women group. 3. Ln(TP), Ln(VLF), Ln(LF) and Ln(HF) of anemic postpartum women group significantly decreased compared with that of normal postpartum women group. Conclusion : The results suggest that the function of heart of anemic postpartum women group significantly decreased compared with that of normal postpartum women group.

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The Change of Heart Rate Variability in Anxiety Disorder after Given Physical or Psychological Stress (불안장애 환자에서 육체적 및 정신적 스트레스 시 심박변이도의 변화)

  • Cho, Min-Kyung;Park, Doo-Heum;Yu, Jaehak;Ryu, Seung-Ho;Ha, Ji-Hyeon
    • Sleep Medicine and Psychophysiology
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    • v.21 no.2
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    • pp.69-73
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    • 2014
  • Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress in anxiety disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 60 anxiety disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity. Differences between HRV indices were evaluated using paired t-tests. Gender difference analysis was accomplished with ANCOVA. Results: SDNN (Standard deviation of normal RR intervals) and low frequency/high frequency (LF/HF) were significantly increased, while NN50, pNN50, and normalized HF (nHF) were significantly decreased in the upright position compared to resting state (p < 0.01). SDNN, root mean square of the differences of successive normal to normal intervals, and LF/HF were significantly increased, while nHF was significantly decreased in the psychological stress state compared to resting state (p < 0.01). SDNN, NN50, pNN50 were significantly lower in upright position compared to psychological stress and nVLF, nLF, nHF, and LF/HF showed no significant differences between them. Conclusion: The LF/HF ratio was significantly increased after both physical and psychological stress in anxiety disorder, but did not show a significant difference between these two stresses. Significant differences of SDNN, NN50, and pNN50 without any differences of nVLF, nLF, nHF, and LF/HF between two stresses might suggest that frequency domain analysis is more specific than time domain analysis.

Circadian Disruptions of Heart rate Variability among Weekly Consecutive-12-hour 2 Shift Workers in the Automobile Factory in Korea (한 자동차공장의 1주연속 12시간주야맞교대근무 노동자들의 심박동수변이)

  • Sung, Ju-Hon;Yum, Myung-Gul;Kong, Jung-Ok;Lee, Hye-Un;Kim, In-A;Kim, Jung-Yeon;Son, Mi-A
    • Journal of Preventive Medicine and Public Health
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    • v.37 no.2
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    • pp.182-189
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    • 2004
  • Objectives : The objective of this study is to compare the circadian patterns of heart rate variability assessed by 24-hour ambulatory electrocardiographic (ECG) recordings during day shift and night shift among the workers in the 5 days-concecutive-12-hour shift in an automobile factory in Korea. Methods : The study population consisted 300 workers, who were randomly selected among the 8700 total workers in one car factory. To analyse circadian variation, the 24-hour ECG recordings (Marquette) were measured during day shift (08:00-20:00 h) and night shift (20:00-08:00 h). Analysis was performed for all time and frequency domain measures of HRV. 233 workers completed taking 24-hour ECG recordings. Results : This study shows that the 24 hourcircadian variation mainly follows work/sleep cycle rather than day/night cycle among shift workers. This study also shows that among the night shift, the circadian variation between work and sleep cycle decreased compared to the work/sleep cycle among day shift workers. All time and frequency domain parameters (except LF/HF ratio) show significantly different between work and sleep in the day shift and night shift. Conclusion : These changes in heart rate variability circadian rhythms reflect significant reductions in cardiac parasympathetic activity with the most marked reduction in normal vagal activity among the shift workers. Especially, it suggests the circadian rhytm has blunted among the night workers. The quantification of the circadian variation in HRV can be a surrogates of workers' potential health risk, as well as suggests possible mechanisms through which the shift works compromise workers' health.

The Usefulness of Comprehensive Diagnosis of Yin-deficiency and Heart Rate Variability in Halitosis Patients (구취 환자에 대한 음허 변증과 심박변이도 검사의 유용성)

  • Son, Ji-Hee;Kim, Jin-Sung;Kang, Kyung;Kim, Ju-Yeon;Seon, Jong-Ki;Han, Ga-Jin;Oh, Seung-Whan;Ryu, Bong-Ha
    • The Journal of Korean Medicine
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    • v.32 no.4
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    • pp.100-110
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    • 2011
  • Objectives: The aim of this study was to investigate the usefulness of a comprehensive diagnosis of yin-deficiency and heart rate variability in halitosis patients. Methods: We surveyed 62 halitosis patients visiting the Halitosis Clinic in the Kyung Hee University Oriental Medicine Hospital from August 2010 to April 2011. The subjects were evaluated on self-assessed severity of halitosis and xerostomia using visual analogue scale (VAS) score and yin-deficiency condition (based on the 10-item Yin-deficiency Questionnaire). Salivary function was measured by the unstimulated salivary flow rate (USFR) and heart rate variability (HRV) parameters were recorded by SA-2000E (Medicore Co. Ltd., Korea). Results: There were substantial significant positive correlations between halitosis, xerostomia VAS scores and yin-deficiency scores. There was significant negative correlation between xerostomia VAS score and USFR. Compared to the normal USFR group (USFR>0.1$m{\ell}$/min), the decreased USFR group (USFR${\leq}0.1m{\ell}$/min) showed significant lower values of Total Power (TP), Lower Frequency (LF), and High frequency (HF). Conclusions: The results of this study suggest that the comprehensive diagnosis of yin-deficiency and HRV are useful in diagnosing of halitosis patients with xerostomia. Therefore, we assume that improvement of yin-deficiency condition can be a potentially effective way to treat halitosis with xerostomia.

Variability of Sea Levels Associated with the Tsushima Current in the Korea Strait (대마난류와 관련된 대한해협 해수면의 변동)

  • LEE Jae-Chul;CHO Kyu-Dae;KIM Soon-Young;KIM Ho-Kyun;SHIM Tae-Bo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.24 no.6
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    • pp.437-449
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    • 1991
  • Time series of barometrically adjusted sea level at Pusan, Izuhara and Hakada are analyzed to study the fluctuations of the Tsushima Current through the Korea Strait. Variability of sea levels and their differences is divided into two parts with respect to the frequency of 0.01 or 0.02 cycles per day(cpd) At lower frequency, both of sea levels and sea level difference(SLD) are coherent and in phase to each other. Pusan has smaller seasonal variations in sea level than other two stations because the effects of geostrophic current and prevailing wind have a negative influence on the seasonal thermosteric contribution to sea level change. Low frequency variability of SLD thus of the Tsushima Current is much greater in the western channel. For higher frequency parts, SLD in the eastern channel has larger variability and is not coherent with that of the western channel. Sea levels at Pusan and Izuhara are $180^{\circ}$ out of phase with SLD in the western and eastern channel respectively, whereas the Hakada level is in phase. This result indicates that eastern channel has a normal response to the along-channel winds and cross-channel geostrophy because Izuhara faces the eastern channel.

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Evaluation of Autonomic Function in Patients with Hyperhidrosis by Power Spectral Analysis of Heart Rate Variability (심박변이도(Heart Rate Variability) 측정을 통한 다한증(多汗症)환자의 자율신경계(自律神經系)기능 평가)

  • Lee, Kun-Young;Lee, Hyung-Koo;Jung, Sung-Ki;Jung, Hee-Jae
    • The Journal of Internal Korean Medicine
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    • v.29 no.1
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    • pp.1-11
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    • 2008
  • Objectives : Essential hyperhidrosis is a socially and occupationally disabling disorder. There are many suggestions that hyperhidrosis is associated with the autonomic nervous system. This study was designed to investigate the autonomic nerve system the patients with hyperhidrosis. Methods : 348 palmar and plantar hyperhidrosis patients and 20 systemic hyperhidrosis patients in the ambulatory care were investigated. All patients were inspected at the first medical examination, using the PSA of HRV. HRV was measured for 5 minutes after 5 minutes' bed rest. We checked the frequency domain analysis of HRV (i.e. TP, VLF, LF, HF and LF/HF) which were transformed into natural logarithm of patients against the standard measures of the HRV components. Then, we compared the means of patients with means and highest values of in the normal range of Koreans 1) between the patients with palmar and plantar hyperhidrosis and the healthy controls and 2) between the patients with the systemic hyperhidrosis and healthy controls, by the frequency domain analysis of heart rate variability (HRV), respectively. We then compared the results between 1) and 2). Results : The values of natural logarithmic measures of LF/HF ratio in the patients with palmar and plantar hyperhidrosis we examined were significantly higher than the values of healthy controls, but those in the patients with systemic hyperhidrosis were not higher. Conclusion : This study suggests that the autonomic nervous function did not simply increase but that the balance between sympathetic and parasympathetic nervous function did matter in patients with palmar and plantar hyperhidrosis. This balance included that the sympathetic nervous function aggravated comparatively with parasympathetic nervous function. On the other hand, we couldn't find any significance of the patients with the systemic hyperhidrosis as for the autonomic nervous function.

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Effects of LI4, Liv3 Acupuncture for Mental Stress on Short-term Analysis of Heart Rate Variability (합곡(合谷)(LI4), 태충(太衝)(Liv3) 자침(刺鍼)이 정신적 스트레스를 가한 정상 성인의 심박변이도에 미치는 영향)

  • Park, Eun-Young;Jang, Jeong-A;Kim, Hyun-Jin;Han, Hyo-Jung;An, Tae-Han;Kim, Jin-Won;Seo, Ho-Seok;Kim, Jin-Yi;Lee, Jin-Hwan
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.4
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    • pp.163-173
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    • 2010
  • Objectives : The objective of this study was to assess the effects of acupuncture applied at 114 and Liv3 points on heart rate variability (HRV) in normal subjects under mental stress. Methods: 36 healthy male and female subjects were recruited and randomized to a treatment group(18 subjects) or a control group (18 subjects). After 10-minutes rest period and instrumentation, both groups performed a mental stress test(Stroop color word test, Arithmetic test. four rule of arithmetic task) for l6-minutes. HRV was recorded before and after the mental stress. And then acupuncture needles were inserted on 114 and Liv3 for the study group. In the control group, they rested for l5-minutes. And Heart rate variability(HRV) was measured. Results: In the both groups, low frequency(LF) power, normalized low frequency power(LF(norm)) and ratio of low frequency to high frequency(LF/HF) was significantly increased after mental stress. Acupuncture induced significant decrease in low frequency(LF) power, normalized low frequency power(LF(norm)) and ratio of low frequency to high frequency (LF/HF) which was increased after mental stress test. In contrast, control group induced no changes. Conclusions : Acupuncture on 114 and Liv3 could be useful to decrease sympathetic activity and prevent the alteration of autonomic nervous system due to mental stress.

Study on Variability of WTP Estimates by the Estimation Methods using Dichotomous Choice Contingent Valuation Data (양분선택형 조건부가치측정(CV) 자료의 추정방법에 따른 지불의사금액의 변동성 연구)

  • Shin, Youngchul
    • Environmental and Resource Economics Review
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    • v.25 no.1
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    • pp.1-25
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    • 2016
  • This study investigated the variability of WTP estimates(i.e. mean or median) with ad hoc assumptions of specific parametric probability distributions(i.e. normal, logistic, lognormal, and exponential distribution) to estimate WTP function using dichotomous choice CV data on mortality risk reduction. From the perspective of policy decision, the variability of these WTP estimates are intolerable in comparison with those of Turnbull nonparametric estimation method which is free from ad hoc distribution assumptions. The Turnbull nonparametric estimation can avoid a kind of misspecification bias due to ad hoc assumption of specific parametric distributions. Furthermore, the WTP estimates by Turnbull nonparametric estimation are robust because the similar estimates are elicited from a dichotomous choice or double dichotomous choice CV data, and the statistically significant WTP estimates can be obtained even though it is not possible by parametric estimation methods. If there are considerable variability among those WTP estimates by parametric estimation methods in condition with no criteria of model adequacy, the mean WTPs from Turnbull nonparametric estimation can be the robust estimates without ad hoc assumptions, which can avoid controversial issues in the perspective of policy decisions.

Clinical Study for Characteristics of Heart Rate Variability in Stroke Patients (중풍 환자의 심박변이도 특성에 대한 임상적 연구)

  • Lee, ln-whan;Shin, Ae-sook;Kim, Na-hee;Kim, Hye-mi;Shim, So-ra;Kim, Min-kyung;Cho, Seung-yeon;Na, Byung-jo;Jung, Woo-sang;Moon, Sang-kwan;Park, Jung-mi;Ko, Chang-nam;Cho, Ki-ho;Kim, Young-suk;Bae, Hyung-sup;Park, Seong-uk
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.11 no.1
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    • pp.1-8
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    • 2010
  • Objectives : We designed this study to investigate difference of heart rate variability(HRV) according to sex, age, acute or chronic phase, category of stroke, national institute of health stroke scale(NIHSS), lesion of stroke. Methods : 64 subjects were recruited from the patients admitted to the department of oriental medicine at East-West Neo Medical Center, Kyung Hee University from 1 September 2009 to 31 August 2010. We compared heart rate(HR), standard deviation of all normal P-P intervals(SDNN), low frequency(LF), high frequency(HF), LF/HF ratio. Results and Conclusions : 1. LF/HF ratio is significantly different between over-70 and below-70 of age. 2. SDNN is significantly different between acute and chronic stroke patients. 3. In sex, category of stroke, national institute of health stroke scale(NIHSS), lesion of stroke, there are no significantly different among the any values of heart rate variability(HRV).

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